Complex Timing of Marsh Harrier Circus aeruginosus Migration Due to Pre- and Post-Migratory Movements

Ardea

Kasper Thorup¹  Mikael Hake²  Thomas Alerstam³  Raymond H.G. Klaassen³  Roine Strandberg³  Patrik Olofsson⁴ 

[1] 4 Zoological Museum, University of Copenhagen, DK-2100 Copenhagen, Denmark;2 Wildlife Damage Centre, Grimsö Wildlife Research Station, Department of Ecology, Swedish University of Agricultural Sciences, SE-730 91 Riddarhyttan, Sweden;1 Department of Animal Ecology, Lund University, Ecology Building, SE-223 62 Lund, Sweden;3 Furubodavägen 73, SE-29692 Yngsjö, Sweden

关键词: Marsh Harrier;   

DOI  :  

学科分类：动物科学

来源: Nederlandse Ornithologische Unie/Netherlands Ornithological Union

【 摘 要 】

Wetrackedthreejuvenileand14adultMarshHarriersCircusaeruginosusfromsouthernSwedenviasatellitetoinvestigatemigrationstrategies.Fourindividualsweretrackedforatleasttwoyears.Allthreejuvenilesandfouroftheadultsmadewest-orientedpre-migratorymovementswellbeforetheonsetofautumnmigration,andtrans-Saharanmigrantsvisitedpost-migratorystopoverareasintropicalAfrica.Bythesemovements,theharrierspresumablyexploitshort-termregionalvariationinfoodabundance.Autumnandspringmigrationoccurredinarelativelynarrowcorridor,withoutdistinctdifferencesbetweensexesintiming,speed,distance,anddurationofmigration,exceptthatfemalestendedtomigratefasterinspringthandidmales.Juvenilesmigratedshorterdistancesthanadults,andmigrationspeedswerelower.Springmigrationwassimilartoautumnmigrationintermsofspeedandduration.JuvenilesdidnotcrosstheSaharaDesertandthreebirds,onefemaleandtwojuveniles,winteredinEurope,whichisinaccordancewitharecentincreaseinthenumberof(juvenile)MarshHarrierswinteringinnorthwesternEurope.AllbirdsthatcrossedtheSaharawinteredintropicalWestAfrica.Harriersshowedsitefidelitytobreeding,winteringandstopoverareas.TheoverallmigrationspeedofMarshHarrierswassimilartothatofOspreysPandionhaliaetusandHoneyBuzzardsPernisapivorus,twoothertrans-Saharanmigrants.Ospreysusefly-and-foragemigrationtopromoteresultingspeed,whereasHoneyBuzzardsareparticularlyapttoexploitthermalsoaring.HowMarshHarriersbalanceforagingversustravellingtoaccomplishtheirrapidmigrationspeedsremainstoberesolved.

【 授权许可】

Unknown